Good link: Harry Day was a contemporary of Douglas Bader - both of whom flew that crazy invention in the first image. The latter took a long break at Oflag IV-C and was one of the "12 apostles" of Goldfinch and Best who designed the Colditz Cock seen in the penultimate image.
Micha, we just like making things, and our laws reflect that. Inventing and creating is fun. Where would we be without fun......no, don't answer that.